Comment by WouterSpaak

I'm no physicist, but I've worked as a software engineer on energy (and drinking water, which EPANET simulates) infrastructure network design tooling for the last six or so years. It has been my understanding that simulating and validating multimodal network designs, which take into account electricity, gas consumption, district heating, is extremely difficult.

Municipalities definitely have systems that document where everything already is under the ground (though especially in Europe there are many older cities where the data of old pipes is lacking), but for designing new energy networks, an "everything" simulation and solving model is very, very complex.